Medical tele-robotic system

ABSTRACT

A robotic system that includes a remote controlled robot. The robot may include a camera, a monitor and a holonomic platform all attached to a robot housing. The robot may be controlled by a remote control station that also has a camera and a monitor. The remote control station may be linked to a base station that is wirelessly coupled to the robot. The cameras and monitors allow a care giver at the remote location to monitor and care for a patient through the robot. The holonomic platform allows the robot to move about a home or facility to locate and/or follow a patient.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application claiming priority to U.S.patent application Ser. No. 10/206,457, filed Jul. 25, 2002, now U.S.Pat. No. 6,925,357.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject matter disclosed generally relates to the field of roboticsused in the medical field.

2. Background Information

There is a growing need to provide remote health care to patients thathave a variety of ailments ranging from Alzheimers to stress disorders.To minimize costs it is desirable to provide home care for suchpatients. Home care typically requires a periodic visit by a health careprovider such as a nurse or some type of assistant. Due to financialand/or staffing issues the health care provider may not be there whenthe patient needs some type of assistance. Additionally, existing staffmust be continuously trained, which can create a burden on trainingpersonnel. It would be desirable to provide a system that would allow ahealth care provider to remotely care for a patient without beingphysically present.

Robots have been used in a variety of applications ranging from remotecontrol of hazardous material to assisting in the performance ofsurgery. For example, U.S. Pat. No. 5,762,458 issued to Wang et al.discloses a system that allows a surgeon to perform minimally invasivemedical procedures through the use of robotically controlledinstruments. There have also been developed “toy” robots for home use.Such robots typically have a relatively simple movement platform andsome type of speech synthesis for generating words and sounds. It wouldbe desirable to provide a robotic system that would allow for remotepatient monitoring and assistance.

BRIEF SUMMARY OF THE INVENTION

A robot that may include a camera and a monitor that are attached to ahousing. The robot may also have a platform that is attached to thehousing and coupled to a controller. The controller may be coupled to abroadband interface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a robotic system;

FIG. 2 is a schematic of an electrical system of a robot;

FIG. 3 is a further schematic of the electrical system of the robot;

FIG. 4 is an illustration of a robot with an arm in an upward position;

FIG. 5 is an illustration of the robot with the arm in a lower position;

FIG. 6 is an illustration of a holonomic platform of the robot;

FIG. 7 is an illustration of a roller assembly of the holonomicplatform;

FIG. 8 is an illustration of an arm assembly of the robot;

FIG. 9 is an illustration of a gripper assembly of the arm;

FIG. 10 is a schematic of a battery recharger for the robot;

FIG. 11 is a vector diagram that may be used to compute movement of therobot.

DETAILED DESCRIPTION

Disclosed is a robotic system that includes a remote controlled robot.The robot may include a camera, a monitor and a holonomic platform allattached to a robot housing. The robot may be controlled by a remotecontrol station that also has a camera and a monitor. The remote controlstation may be linked to a base station that is wirelessly coupled tothe robot. The cameras and monitors allow a care giver at the remotelocation to monitor and care for a patient through the robot. Theholonomic platform allows the robot to move about a home or facility tolocate and/or follow a patient.

Referring to the drawings more particularly by reference numbers, FIG. 1shows a robotic system 10. The robotic system 10 includes a robot 12, abase station 14 and a remote control station 16. The remote controlstation 16 may be coupled to the base station 14 through a network 18.By way of example, the network 18 may be either a packet switchednetwork such as the Internet, or a circuit switched network such has aPublic Switched Telephone Network (PSTN) or other broadband system. Thebase station 14 may be coupled to the network 18 by a modem 20 or otherbroadband network interface device.

The remote control station 16 may include a computer 22 that has amonitor 24, a camera 26, a microphone 28 and a speaker 30. The computer22 may also contain an input device 32 such as a joystick or a mouse.The control station 16 is typically located in a place that is remotefrom the robot 12. Although only one remote control station 16 is shown,the system 10 may include a plurality of remote stations. Additionally,although only one robot 12 is shown, it is to be understood that thesystem 10 may have a plurality of robots 12. In general any number ofrobots 12 may be controlled by any number of remote stations. Forexample, one remote station 16 may be coupled to a plurality of robots12, or one robot 12 may be coupled to a plurality of remote stations 16.

The robot 12 includes a movement platform 34 that is attached to a robothousing 36. Also attached to the robot housing 36 are a camera 38, amonitor 40, a microphone(s) 42 and a speaker 44. The microphone 42 andspeaker. 30 may create a stereophonic sound. The robot 12 may also havean antennae 44 that is wirelessly coupled to an antennae 46 of the basestation 14. The system 10 allows a user at the remote control station 16to move the robot 12 through the input device 32. The robot camera 38 iscoupled to the remote monitor 24 so that a user at the remote station 16can view a patient. Likewise, the robot monitor 40 is coupled to theremote camera 26 so that the patient can view the user. The microphones28 and 42, and speakers 30 and 44, allow for audible communicationbetween the patient and the user.

The remote station computer 22 may operate Microsoft OS software andWINDOWS XP or other operating systems such as LINUX. The remote computer22 may also operate a video driver, a camera driver, an audio driver anda joystick driver. The video images may be transmitted and received withcompression software such as MPEG CODEC.

FIGS. 2 and 3 show an embodiment of the robot 12. The robot 12 mayinclude a high level control system 50 and a low level control system52. The high level control system 50 may include a processor 54 that isconnected to a bus 56. The bus is coupled to the camera 38 by aninput/output (I/O) port 58, and to the monitor 40 by a serial outputport 60 and a VGA driver 62. The monitor 40 may include a touchscreenfunction that allows the patient to enter input by touching the monitorscreen.

The speaker 44 is coupled to the bus 56 by a digital to analog converter64. The microphone 42 is coupled to the bus 56 by an analog to digitalconverter 66. The high level controller 50 may also contain randomaccess memory (RAM) device 68, a non-volatile RAM device 70 and a massstorage device 72 that are all coupled to the bus 62. The mass storagedevice 72 may contain medical files of the patient that can be accessedby the user at the remote control station 16. For example, the massstorage device 72 may contain a picture of the patient. The user,particularly a health care provider, can recall the old picture and makea side by side comparison on the monitor 24 with a present video imageof the patient provided by the camera 38. The robot antennae 44 may becoupled to a wireless transceiver 74. By way of example, the transceiver74 may transmit and receive information in accordance with IEEE 802.11a.

The controller 54 may operate with a LINUX OS operating system. Thecontroller 54 may also operate X WINDOWS along with video, camera andaudio drivers for communication with the remote control station 16.Video information may be transceived using MPEG CODEC compressiontechniques. The software may allow the user to send e-mail to thepatient and vice versa, or allow the patient to access the Internet. Ingeneral the high level controller 50 operates to control thecommunication between the robot 12 and the remote control station 16.

The high level controller 50 may be linked to the low level controller52 by serial ports 76 and 78. The low level controller 52 includes aprocessor 80 that is coupled to a RAM device 82 and non-volatile RAMdevice 84 by a bus 86. The robot 12 contains a plurality of motors 88and motor encoders 90. The encoders 90 provide feedback informationregarding the output of the motors 88. The motors 88 can be coupled tothe bus 86 by a digital to analog converter 92 and a driver amplifier94. The encoders 90 can be coupled to the bus 86 by a decoder 96. Therobot 12 also has a number of proximity sensors 98 (see also FIG. 1).The position sensors 98 can be coupled to the bus 86 by a signalconditioning circuit 100 and an analog to digital converter 102.

The low level controller 52 runs software routines that mechanicallyactuate the robot 12. For example, the low level controller 52 providesinstructions to actuate the movement platform to move the robot 12, orto actuate an arm of the robot. The low level controller 52 may receivemovement instructions from the high level controller 50. The movementinstructions may be received as movement commands from the remotecontrol station. Although two controllers are shown, it is to beunderstood that the robot 12 may have one controller controlling thehigh and low level functions.

The various electrical devices of the robot 12 may be powered by abattery(ies) 104. The battery 104 may be recharged by a batteryrecharger station 106 (see also FIG. 1). The low level controller 52 mayinclude a battery control circuit 108 that senses the power level of thebattery 104. The low level controller 52 can sense when the power fallsbelow a threshold and then send a message to the high level controller50. The high level controller 50 may include a power management softwareroutine that causes the robot 12 to move so that the battery 104 iscoupled to the recharger 106 when the battery power falls below athreshold value. Alternatively, the user can direct the robot 12 to thebattery recharger 106. Additionally, the battery may be replaced or therobot 12 may be coupled to a wall power outlet by an electrical cord(not shown).

FIG. 4 shows an embodiment of the robot 12. The robot 12 may include aholonomic platform 110 that is attached to a robot housing 112. Theholonomic platform 110 allows the robot 12 to move in any direction.Although not shown the robot housing 112 may include bumpers.

The robot 12 may have an arm 114 that supports the camera 38 and monitor40. The arm 114 may have two degrees of freedom so that the camera 26and monitor 24 can be moved from an upper position shown in FIG. 4 to alower position shown in FIG. 5. The arm 114 may have an end effector 116such as a gripper that can grasp objects.

The robot 12 may include a drawer 118 that can automatically movebetween a closed position and an open position. The drawer 118 can beused to dispense drugs to a patient. For example, the drawer 118 mayinclude a drug(s) that must be taken at a certain time. The robot 12 maybe programmed so that the drawer 118 is opened at the desired time. Anurse or other health care provider may periodically “load” the drawer118. The robot may also have a battery recharger port 119. Althoughdrugs are described, it is to be understood that the drawer 118 couldhold any item.

As shown in FIG. 6 the holonomic platform 110 may include three rollerassemblies 120 that are mounted to a base plate 122. The rollerassemblies 120 are typically equally spaced about the platform 110 andallow for movement in any direction.

FIG. 7 shows an embodiment of a roller assembly 120. Each assembly 120may include a drive ball 124 that is driven by a pair of transmissionrollers 126. The assembly 120 includes a retainer ring 128 and aplurality of bushings 130 that allow the ball 124 to rotate in an x andy direction but prevents movement in a z direction.

The transmission rollers 126 are coupled to a motor assembly 132. Theassembly 132 corresponds to the motor 88 shown in FIG. 3. The motorassembly 132 includes an output pulley 134 attached to a motor 136. Theoutput pulley 134 is coupled to a pair of ball pulleys 138 by a drivebelt 140. The ball pulleys 138 are attached to drive pins 142 that areattached to a transmission bracket 144. The transmission rollers 126 areattached to a transmission bracket 144 by a roller pin 146. Thetransmission brackets 144 each have a pin 143 that is supported by apart of the housing.

Rotation of the output pulley 134 rotates the ball pulleys 138. Rotationof the ball pulleys 138 causes the transmission rollers 126 to rotateand spin the ball 124 through frictional forces. Spinning the ball 124will move the robot 12. The drive balls 126 are out of phase so that oneof the balls 126 is always in contact with ball 124. The roller pin 146and bracket 144 allow the transmission rollers 126 to freely spin andallow orthoganal directional passive movement when one of the otherroller assemblies 120 is driving and moving the robot 12.

FIGS. 8 and 9 show an embodiment of the arm 114. The arm 114 may includea first linkage 150 that is pivotally mounted to a fixed plate 152 ofthe robot housing 12. The arm 114 may also include a second linkage 154that is pivotally connected to the first linkage 150 and a third linkage156 that is pivotally connected to the second linkage 154.

The first linkage 150 may be coupled to a first motor 158 and motorencoder 160 by a gear assembly 162. Rotation of the motor 158 will causea corresponding pivotal movement of the linkage 150 and arm 114. Thelinkage 150 may be coupled to the fixed plate 152 by a bearing 164.

The second linkage 154 may be coupled to a second motor 166 and encoder168 by a gear assembly 170 and a pulley assembly 172. The pulleyassembly 172 may be connected to the gear assembly 170 by a pin 174 thatextends through the gear assembly 162 of the first motor 158. The secondlinkage 154 may be attached to a pin 176 that can spin relative to thefirst linkage 150. The pulley assembly 172 may have a belt 178 thatcouples a pair of pulleys 180 and 182 that are attached to pins 174 and176, respectively. Pin 176 may be coupled to the first linkage 150 bybearings 182. The arm 114 is configured to allow wires 183 to beinternally routed through the linkages 150, 154 and 156.

The third linkage 156 may be connected to a pin 184 that can spinrelative to the second linkage 154. The pin 184 may be coupled to thesecond linkage 154 by a bearing assembly 186. The third linkage 156 maybe structurally coupled to the first linkage 150 by a pair of pulleyassemblies 188. The pulley assembly 188 insures a horizontal position ofthe third linkage 156 no matter what position the first 150 and second154 linkages are in. As shown in FIGS. 4 and 5 the third linkage 156 isalways in a horizontal position. This insures that the camera 26 isalways in the same orientation, thus reducing the possibility ofdisorientation at the remote control station when viewing the patient.

The gripper 116 is attached to the third linkage 156. The gripper 116may include a pair of fingers 190 that are pivotally attached to a baseplate 192. The fingers 190 are coupled to a motor 194 and encoder 196 bya gear assembly 198. The base plate 192 is coupled to the third linkage156 by a bearing assembly 200. The motor 194 can spin the base plate 192and fingers 192 relative to the third linkage 156.

The gripper 116 may further have a push rod 202 that can engage camsurfaces 204 of the fingers 190 to move the gripper fingers 190 betweenopen and closed positions. The push rod 202 may be coupled to a motor206 and encoder (not shown) by a linkage assembly 208. Actuation of themotor 206 will translate the push rod 202 and move the fingers 190. Themotor 206 may have a force sensor that provides force feedback back tothe remote control station. The input device of the remote controlstation may have a force feedback mechanism so that the user feels theforce being exerted onto the gripper fingers 190.

In operation, the robot 12 may be placed in a home or a facility whereone or more patients are to be monitored and/or assisted. The facilitymay be a hospital or a residential care facility. By way of example, therobot 12 may be placed in a home where a health care provider maymonitor and/or assist the patient. Likewise, a friend or family membermay communicate with the patient. The cameras and monitors at both therobot and remote control station allow for teleconferencing between thepatient and the person at the remote station.

The robot 12 can be maneuvered through the home or facility bymanipulating the input device 32 at the remote station 16. The robot 12may also have autonomous movement. For example, the robot 12 may beprogrammed to automatically move to a patients room at a certain time todispense drugs in the drawer 118 without input from the remote station16. The robot 12 can be programmed to monitor and/or assist a patient 24hours a day, 7 days a week. Such a monitoring capability is enhanced bythe autonomous recharging function of the robot.

The robot 10 may be controlled by a number of different users. Toaccommodate for this the robot may have an arbitration system. Thearbitration system may be integrated into the operating system of therobot 12. For example, the arbitration technique may be embedded intothe operating system of the high-level controller 50.

By way of example, the users may be divided into classes that includethe robot itself, a local user, a caregiver, a doctor, a family member,or a service provider. The robot may override input commands thatconflict with robot operation. For example, if the robot runs into awall, the system may ignore all additional commands to continue in thedirection of the wall. A local user is a person who is physicallypresent with the robot. The robot could have an input device that allowslocal operation. For example, the robot may incorporate a voicerecognition system that receives and interprets audible commands.

A caregiver is someone who remotely monitors the patient. A doctor is amedical professional who can remotely control the robot and also accessmedical files contained in the robot memory. The family and serviceusers remotely access the robot. The service user may service the systemsuch as by upgrading software, or setting operational parameters.

Message packets may be transmitted between a robot 12 and a remotestation 16. The packets provide commands and feedback. Each packet mayhave multiple fields. By way of example, a packet may include an IDfield a forward speed field, an angular speed field, a stop field, abumper field, a sensor range field, a configuration field, a text fieldand a debug field.

The identification of remote users can be set in an ID field of theinformation that is transmitted from the remote control station 16 tothe robot 12. For example, a user may enter a user ID into a setup tablein the application software run by the remote control station 16. Theuser ID is then sent with each message transmitted to the robot.

The robot 12 may operate in one of two different modes; an exclusivemode, or a sharing mode. In the exclusive mode only one user has accesscontrol of the robot. The exclusive mode may have a priority assigned toeach type of user. By way of example, the priority may be in order oflocal, doctor, caregiver, family and then service user. In the sharingmode two or more users may share access with the robot. For example, acaregiver may have access to the robot, the caregiver may then enter thesharing mode to allow a doctor to also access the robot. Both thecaregiver and the doctor can conduct a simultaneous tele-conference withthe patient.

The arbitration scheme may have one of four mechanisms; notification,timeouts, queue and call back. The notification mechanism may informeither a present user or a requesting user that another user has, orwants, access to the robot. The timeout mechanism gives certain types ofusers a prescribed amount of time to finish access to the robot. Thequeue mechanism is an orderly waiting list for access to the robot. Thecall back mechanism informs a user that the robot can be accessed. Byway of example, a family user may receive an e-mail message that therobot is free for usage. Tables 1 and 2, show how the mechanisms resolveaccess request from the various users.

TABLE I Access Medical Command Software/Debug Set User Control RecordOverride Access Priority Robot No No Yes (1) No No Local No No Yes (2)No No Caregiver Yes Yes Yes (3) No No Doctor No Yes No No No Family NoNo No No No Service Yes No Yes Yes Yes

TABLE II Requesting User Local Caregiver Doctor Family Service CurrentUser Local Not Allowed Warn current user of Warn current user of Warncurrent user of Warn current user of pending user pending user pendinguser pending user Notifying requesting Notifying requesting userNotifying requesting user Notifying requesting user that system is thatsystem is in use that system is in use user that system is in in use Settimeout = 5 m Set timeout = 5 m use Set timeout Call back No timeoutCall back Caregiver Warn current user Not Allowed Warn current user ofWarn current user of Warn current user of of pending user. pending userpending user pending user Notify requesting Notify requesting userNotify requesting user Notify requesting user that system is that systemis in use that system is in use user that system is in in use. Settimeout = 5 m Set timeout = 5 m use Release control Queue or callback Notimeout Callback Doctor Warn current user Warn current user of Warncurrent user of Notify requesting user Warn current user of of pendinguser pending user pending user that system is in use pending user Notifyrequesting Notify requesting Notify requesting user No timeout Notifyrequesting user that system is user that system is that system is in useQueue or callback user that system is in in use in use No timeout useRelease control Set timeout = 5 m Callback No timeout Callback FamilyWarn current user Notify requesting Warn current user of Warn currentuser of Warn current user of of pending user user that system is pendinguser pending user pending user Notify requesting in use Notifyrequesting user Notify requesting user Notify requesting user thatsystem is No timeout that system is in use that system is in use userthat system is in in use Put in queue or Set timeout = 1 m Set timeout =5 m use Release Control callback Queue or callback No timeout CallbackService Warn current user Notify requesting Warn current user of Warncurrent user of Not Allowed of pending user user that system is requestpending user Notify requesting in use Notify requesting user Notifyrequesting user user that system is No timeout that system is in usethat system is in use in use Callback No timeout No timeout No timeoutCallback Queue or callback

The information transmitted between the station 16 and the robot 12 maybe encrypted. Additionally, the user may have to enter a password toenter the system 10. A selected robot is then given an electronic key bythe station 16. The robot 12 validates the key and returns another keyto the station 16. The keys are used to encrypt information transmittedin the session.

FIG. 10 shows an embodiment of a battery recharger. The robot port 119may include a secondary winding 250 that is magnetically coupled to aprimary winding 252 of the battery recharger station 106. The primarywinding 252 is coupled to an electrical outlet plug 254 by a relaycircuit 256, a fuse 258 and a switch 260. The relay 256 is controlled bya recharger controller 262.

The recharger controller 262 is connected to a recharger infrared (IR)transceiver 264. The recharger IR transceiver 264 is coupled to a robotIR transceiver 266. The robot IR transceiver 266 is connected to the lowlevel controller 52. The robot 10 may also have an alignment sensor 268that can sense a target 270 on the station 106. By way of example, thesensor 268 may include an optical emitter and receiver that detects alight beam reflected from the target 270. The controller 52 may alsosense a current flow into the battery 104 to determine whether the robot12 is aligned with the docking station 106.

The secondary windings 250 are connected to the battery 104 by a chargercircuit 272. The secondary 250 and primary 252 windings may each havewires 274 wrapped about a magnetic core 276. The station 106 may alsohave an oscillator/chopper circuit (not shown) to increase the voltagemagnetically transferred to the secondary winding 250.

In operation, the robot 10 is moved to the battery recharger station 106either autonomously, or by user control. The robot 10 is moved until thesensor 268 is aligned with the target 270. The low level controller 52then sends a command to the recharger controller 262 through thetransceivers 264 and 266. The recharger controller 262 then closes therelay 256 wherein power is transferred to the battery 104 through thewindings 250 and 252. When the battery 104 is recharged, or the batteryrecharging process is interrupted by the user, the low level controller52 transmits a command to the recharger controller 262 to open the relay256. The robot 10 then moves away from the recharging station 106.

FIG. 11 shows a vector diagram that can be used to compute movement ofthe robot with the following equations:

$\begin{matrix}{w_{1} = {{\frac{V}{R_{1}}\left( {{Sin} \propto_{1}{{{Sin}\mspace{11mu}\theta} - {Cos}} \propto_{1}{{Cos}\mspace{11mu}\theta}} \right)} + \frac{\Psi\; L_{1}}{R_{1}}}} & (1) \\{w_{2} = {{\frac{V}{R_{2}}\mspace{11mu}{Sin}\mspace{11mu}\theta} + \frac{\Psi\; L_{2}}{R_{2}}}} & (2) \\{w_{3} = {{\frac{V}{R_{3}}\left( {{Sin} \propto_{3}{{{Sin}\mspace{11mu}\theta} + {Cos}} \propto_{3}{{Cos}\mspace{11mu}\theta}} \right)} + \frac{\Psi\; L_{3}}{R_{3}}}} & (3)\end{matrix}$

where,

w₁=is the drive angular velocity of a first ball 124.

w₂=is the drive angular velocity of a second ball 124.

w₃=is the drive angular velocity of a third ball 124.

V=is the input linear velocity for the robot. V has components V_(x) andV_(y), where; V_(x)=|V|cos θ and V_(y)=|V|sin θ.

ψ=is the input angular velocity for the robot.

Let the angular velocity vector w=[w₁, w₂, w₃]^(T). (4)

$\begin{matrix}{A = \begin{bmatrix}{- \frac{{Cos} \propto_{1}}{R_{1}}} & \frac{{Sin} \propto_{1}}{R_{1}} & \frac{L_{1}}{R_{1}} \\O & {- \frac{1}{R_{2}}} & \frac{L_{2}}{R_{2}} \\\frac{{Cos} \propto_{3}}{R_{3}} & \frac{{Sin} \propto_{3}}{R_{3}} & \frac{L_{3}}{R_{3}}\end{bmatrix}} & (5)\end{matrix}$

and the velocity vector:V=[vx, vy, ψ] ^(T)  (6)W=A·V  (7)

The angular velocity vector w is calculated from equation (7) andcompared with the actual w valves measured by the motor encoder. Analgorithm performs an error correction routine to compensate fordifferences in the actual and desired valves.

While certain exemplary embodiments have been described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative of and not restrictive on the broad invention, andthat this invention not be limited to the specific constructions andarrangements shown and described, since various other modifications mayoccur to those ordinarily skilled in the art.

1. A method that allows a person to remotely visit a patient located ina healthcare facility, comprising: accessing a robot from a remotestation; capturing video and audio of the patient by the robot;transmitting the video and audio of the patient to the remote station;displaying the video of the patient at the remote station; generatingthe audio of the patient at the remote station; capturing video andaudio of the person at the remote station transmitting the video andaudio of the person to the robot; displaying the video of the person ona monitor of the robot; generating the audio of the person at the robot;transmitting a command from the remote station to move the robot; and,moving the robot across a surface of the healthcare facility in responseto the transmitted command.
 2. The method of claim 1, wherein thecommand, and the audio and video of the patient and the person aretransmitted through a broadband network.
 3. The method of claim 1,wherein the robot is located in a hospital.
 4. The method of claim 1,wherein the robot is located in a residential care facility.
 5. Themethod of claim 1, further comprising logging onto the remote stationwith a password.
 6. The method of claim 1, wherein the transmitted videoand audio are encrypted.
 7. The method of claim 1, further comprising afamily priority assignment that is transmitted to the robot.